1. Field of the Invention
The present invention relates to a component having at least one MEMS (micro-electromechanical system) element and having at least one cap made of a semiconductor material, the micromechanical structure of the MEMS element being situated in a cavity between a carrier and the cap and including at least one structural element, which is deflectable out of the element plane within the cavity.
2. Description of the Related Art
Components having MEMS elements have been manufactured in mass production for some years for greatly varying applications, for example, in the field of automotive technology and consumer electronics. The MEMS element may be a sensor element having detection means for detecting the deflection of the micromechanical structural element or also an actuator element having drive means for activating the deflectable structural element. The cap protects the micromechanical structure of the MEMS element from environmental influences, such as particles, moisture, and aggressive environmental media. In addition, defined pressure conditions may be produced within the cavity if the cap is installed in a hermetically sealed way.
A concept for a vertical hybrid integrated component is presented in US Patent Application Publication No. 2011/0049652 A1, according to which a chip stack is formed from an ASIC, a MEMS, and a cap. In the method described here, the starting substrate for the MEMS element is bonded onto an already processed ASIC substrate. Only thereafter is a micromechanical structure produced in the MEMS substrate, which includes at least one deflectable structural element. Independently thereof, a cap is structured from a semiconductor material and prepared for the installation above the micromechanical structure of the MEMS substrate, on the ASIC substrate. The cap wafer thus processed is bonded after the structuring of the MEMS substrate onto the ASIC substrate, so that the micromechanical structure is enclosed hermetically sealed in a cavity between the ASIC substrate and the cap.
The component described in US Patent Application Publication No. 2011/0049652 A1 is equipped with a capacitor system, which—depending on the MEMS function—may be used for detecting externally caused deflections of the structural element or also for activating, i.e., for moving, the deflectable structural element. For this purpose, the capacitor system includes at least one deflectable electrode on the deflectable structural element of the MEMS element and stationary electrodes, which are implemented here in a structured metal layer on the surface of the ASIC substrate.